TEHRAN, Iran — It took the images of large numbers of dead children lined up in neat rows, snuffed out by a method of warfare that breached Obama’s so-called "red line," for the US administration to seriously consider the prospect of intervening militarily in Syria for the first time since the conflict erupted in spring 2011.
Aside from providing definitive evidence that the regime — and not the rebels he supports — is responsible for the attack, Obama must demonstrate he has exhausted all diplomatic efforts to de-escalate the crisis before he can justifiably go to war. This means talking to Iran.